I am a first time betta breeder. I have a 10 G tank I put the male in and I put the female in a glass chimney. They got along well rubbing up against the glass and she was doing the head down display etc. After several days I let her out of the chimney and watched them for several hours for unwanted behavior. They were doing just fine so I went out for a few hours. When I came home the female had bitten the daylights out of the males tail and fins. I took him out and put him back into his 2.5 G tank. I had just done a full water change in it when he was moved to the 10 G. When I put him back in I added Stress Zyme, Novaqua, and an almond leaf. I also gave him a new airstone. Should there be more than what I am doing? I don't want to lose him, his is one of my most beautiful males.

Did you condition the two of them for a few weeks prior to this? It's important that you do so the female starts to get eggy and wants to breed since the timing would be good.

To help his fins, just clean water should do as well as a high protein diet. If you conditioned him first, this will help him regrow his fins a lot faster too since he has all of those resources to draw upon.

It's best if you watch your breeding pair together very closely for the entire day to make sure. Sometimes things go awry.

This is the risk we all run when attempting to breed our fish. I had a female do the same thing to one of my top males... they eventually gave me a spawn and the male recuperated fully but it can be terrifying when you have such a gorgoeus male.
I almost didn't breed the male in my avatar because I didn't want his fins nipped but he came out unharmed... it's all about proper conditioning and knowing when the pair is ready, imo.

Add salt to his water along with the IAL and keep it clean, his fins will never be the same but he will recuperate.